In recent years, as a manufacturing line for a semiconductor device, minimal fabrication systems have been proposed in which basically one device is manufactured in a 0.5 inch size (half inch size) wafer, the manufacturing step is therefore composed of plural portable unit treatment devices, these plural unit treatment devices are easily re-arranged in flow shops and job shops, and thereby the minimal fabrication systems can properly cope with extremely small quantity production and multi-kind production (refer to Patent Literature 1 for example).
Also, with respect to a developing device used for the minimal fabrication system, a spin developing device has been proposed in which it is configured to rotate a wafer slowly at a rotation speed of a degree a developing solution is not spilled out from the top of the wafer in a state the developing solution of a quantity less than a quantity spilled out from the top of the wafer is dropped onto the wafer (refer to Patent Literature 2 for example).